The Dr. Nancy Foster Florida Keys Environmental Center in Key West, Fla., serves the Florida Keys National Marine Sanctuary. It is fitting that when the new environmental center needed a roof system, a green roof was chosen for part of the building.
However, the green roof system installation also presented a milestone—it is believed to be the first commercial green roof system installed in south Florida, according to Michael Levine, president of Murton Roofing, Miami, a Tecta America company, the roofing contractor who installed the green roof system.
"We believe our project is the third green roof in Florida, first in south Florida and southernmost green roof in the U.S.," Levine says.
Murton Roofing found the project while doing a search of federal projects.
"We were chosen for many reasons, including our proximity to the job site; manufacturer approvals; ability to perform roofing and waterproofing; ability to draw on the experience of Magco Inc., Jessup, Md., one of our partner companies under the Tecta America umbrella that has installed many green roofs near its headquarters in Maryland; competitive pricing; and reputation for quality work," Levine says.
The company was hired to install roof systems, including a green roof system, on the three buildings of the Dr. Nancy Foster Florida Keys Environmental Center.
"The three buildings combined are more than 25,000 square feet, including about 4,000 square feet of green roof space on a terrace on Building B," Levine says. "The entire roof has a concrete deck, and we installed a variety of insulation and coatings on the traditional roof areas."
On the green roof area, the company installed 1,300 square feet of patio pavers, as well as American Hydrotech's Monolithic Membrane 6125® roofing/waterproofing membrane with a topping that includes drainage mats, soil and plants. It took about three days to install the entire green roof system.
On the concrete deck, Murton Roofing first installed surface conditioner (concrete primer) and hot rubberized asphalt. Then, a polyester mat (reinforcement sheet), hot rubberized asphalt and root barrier/cap sheet were installed.
Next, Murton Roofing installed insulation board, a moisture retention mat and a molded drainage panel. After installing the filter fabric, the company installed specially blended, weed-free soil media.
The next day, Murton Roofing installed Gulf cordgrass, which is indigenous to the Florida Keys, and Yellowtop plants.
"The green roof section features a terrace that is accessible from the second floor," Levine says. "Pavers will allow visitors to stand in the fresh air and get a closer look at the indigenous greenery planted on the roof."
Weight issues that often are a concern with green roof system installation were not a problem.
"The older, reroofed structure received a standard modified bitumen roof, so there were no special weight considerations," Levine says. "The rest of the roofs, including the green roof, were part of the original design of new structures."
During the project, Murton Roofing used various safety precautions, including fall-protection measures such as perimeter warning lines and a safety monitor.
Murton Roofing faced various challenges during the project.
"There were minor issues for the delivery company once it reached the Keys," Levine says. "The company had to make two trips from the weigh station because the dirt for the green roof exceeded local weight limits for its truck."
Distance also was an issue.
"Distance can complicate overall coordination, and this project is far enough from the nearest Murton Roofing office that we had to provide lodging for our crews at various times during the last nine months of the project," Levine says. "This got expensive when we hit the Keys' in-season months and hotel rates were three times or four times the amount of autumn rates."
The company benefited from the help of Magco.
Magco helped Murton Roofing bid the job and assisted in estimating. It also provided some labor for the project.
"We had crews working in Miami and sent them to Key West to help install the green portion of the roof," says Mark Gaulin, president of Magco. "Florida has a green roof initiative right now, so this was its first step."
There were some differences between installing a green roof and installing a traditional roof.
"From the concrete deck up to the insulation layer, this system is a typical inverted roof membrane assembly," Levine says. "The difference here, obviously, is the five extra layers—plants, soil media, filter, drainage and retention. Additionally, a flood test was performed to ensure the assembly is watertight because it sometimes will hold a lot of water."
The chance to be a part of the green roof movement was satisfying.
"We've been installing roof systems for 30 years, so it is exciting for us to embrace the newest technologies and install them successfully," Levine says. "We see green roofs as a particularly important and timely development in roofing, and we are proud to be the leader in south Florida.
"The extraordinary benefits of green roofs—and green construction in general—are just beginning to garner some real attention," he continues. "We anxiously look forward to the next green roof opportunity."
Krista Reisdorf is managing editor of Professional Roofing magazine.
Project name: Dr. Nancy Foster Florida Keys Environmental Center
Project location: Key West, Fla.
Project duration: April 24-April 26 (green roof section)
Roof system type: Green
Roofing contractor: Murton Roofing, Miami, a Tecta America company
Roofing manufacturer: American Hydrotech, Chicago